Effect of chemical and integrated weed management in upland rice

Abstract

An experiment was conducted to study the effect of different weed management practices in upland rice in Kerala. The average reduction in grain yield due to weed competition was 44 per cent in 1988 and 56 per cent in 1989. During both the years weed free plots recorded grain yield on par with pre-emergence butachlor + 2,4-D at 25 to 30 days after rice emergence (DARE), pre-emergence pendimethalin and pre-emergence pendimethalin followed by either hand weeding once or 2,4-D application at 25 to 30 DARE. Weed control achieved by preemergence application of pendimelhalin followed by either a post emergence application of 2,4-D or hand weeding once was as effective as maintaining weed free condition throughout the crop growth. Weed control efficiency was higher in the case of pendimathalin when compared to thiobencarb and butachlor.